Defense: Tsarnaev repeatedly asked for lawyer

10/7/13 6:28 PM EDT

Accused Boston Marathon bomber Dzhokhar Tsarnaev made "repeated requests" for an attorney while he was hospitalized with grave injuries after his arrest, according to a filing his defense made with the federal court in Boston Monday.

In a motion seeking more information from the government about the episodes, Tsarnaev's defense lawyers suggest that the requests were ignored or refused.

"While the government has produced information regarding the interrogation, it is not known whether Mr. Tsarnaev’s requests for counsel from his hospital bed were ever communicated to the Court. The defense therefore has requested and persists in requesting any communications among law enforcement, prosecutors, and the Court concerning Mr. Tsarnaev’s requests for counsel in order to fully assess what remedies may be available for violations of the Fifth and Sixth Amendments," wrote the defense lawyers, led by San Diego attorney Judy Clarke and federal defender Miriam Conrad.

Tsarnaev was arrested following a shootout in Watertown, Mass., a few days after bombs went off at the finish line of the Boston Marathon on April 15, 2013, killing three and wounding scores more. He was charged in an initial criminal complaint in April. In June, he was charged in an indictment that accused him of joining in a conspiracy with his brother, Tamerlan, to kill the three victims at the marathon and a campus police officer. (Tamerlan was killed in the April confrontation with police.)

The U.S. Attorney's Office in Boston didn't immediately respond to a request for comment on the motion. Law enforcement officials have stressed that Dzhokhar Tsarnaev was not read his rights by the FBI before he was arraigned by a federal judge at the hospital on April 22.

The federal charges carry the potential for the death penalty, though prosecutors have not signaled yet whether it will be sought in this case. Tsarnaev's defense is expected to focus on helping him escape the death penalty either at trial, through a plea deal with the government, or through a decision by the Justice Department not to seek capital punishment in the case.